Synthesis of Lipoteichoic Acids in Bacillus anthracis
Synthesis of Lipoteichoic Acids in Bacillus anthracis
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DOI：
10.1128/jb.00626-12
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发表时间：
2012-08-01
影响因子：
3.2
通讯作者：
Missiakas, Dominique
中科院分区：
文献类型：
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作者：
Garufi, Gabriella;Hendrickx, Antoni P.;Missiakas, Dominique
脂磷壁酸(LTA)是一种甘油磷酸盐聚合物，是革兰氏阳性细菌包膜的一种成分，迄今在炭疽杆菌中尚未发现。金黄色葡萄球菌和其他微生物中LTA的合成是由ltas基因的产物催化的，ltas基因是一种膜蛋白，可以从磷脂酰甘油聚合聚甘油磷酸。在此，我们在炭疽芽孢杆菌基因组中鉴定了四个ltas同源物，命名为ltaS1至-4。用聚甘油磷酸单抗检测炭疽杆菌Sterne(pXO1(+)pXO2(-))繁殖型包膜LTA。缺少ltaS1、ltaS2、ltaS3或ltaS4的炭疽杆菌突变体没有表现出生长或LTA合成缺陷。相反，缺乏ltaS1和ltaS2的炭疽杆菌菌株不能合成LTA，表现为活力降低，被膜形态改变，营养体型分离异常，产孢率降低。在炭疽杆菌和其他微生物中单独表达ItaS1或ltaS2足以合成聚磷酸甘油。因此，与金黄色葡萄球菌类似，炭疽杆菌使用LTA酶来合成LTA，LTA是一种促进细菌生长和细胞分裂的包膜成分。
Lipoteichoic acid (LTA), a glycerol phosphate polymer, is a component of the envelope of Gram-positive bacteria that has hitherto not been identified in Bacillus anthracis, the causative agent of anthrax. LTA synthesis in Staphylococcus aureus and other microbes is catalyzed by the product of the ltaS gene, a membrane protein that polymerizes polyglycerol phosphate from phosphatidyl glycerol. Here we identified four ltaS homologues, designated ltaS1 to -4, in the genome of Bacillus anthracis. Polyglycerol phosphate-specific monoclonal antibodies were used to detect LTA in the envelope of B. anthracis strain Sterne (pXO1(+) pXO2(-)) vegetative forms. B. anthracis mutants lacking ltaS1, ltaS2, ltaS3, or ltaS4 did not display defects in growth or LTA synthesis. In contrast, B. anthracis strains lacking both ltaS1 and ltaS2 were unable to synthesize LTA and exhibited reduced viability, altered envelope morphology, aberrant separation of vegetative forms, and decreased sporulation efficiency. Expression of ItaS1 or ltaS2 alone in B. anthracis as well as in other microbes was sufficient for polyglycerol phosphate synthesis. Thus, similar to S. aureus, B. anthracis employs LtaS enzymes to synthesize LTA, an envelope component that promotes bacterial growth and cell division.